Intelligence
Also see: Development of intelligence, Intelligence on Earth, Intelligent aliens Intelligence is hard to define exactly: it can be interpreted as a mental feature, or a set of features, that involve reasoning, planning, goal-oriented behaviour, learning from experience, abstract thought and projection, problem-solving and intentional self-adaptation to the circumstances. A great number of speculative-biology projects, especially those about extraterrestrial life, try to include high, human-like intelligence for at least one species, for it's necessary to derive from biological interactions the extremely complex structures and behaviours that form a civilization such as ours. Features of intelligence Of course, living organisms cannot simply be divided as intelligent and not-intelligent. Being as complex as it is, it can be broken up in many characteristics, degrees and specializations. Xenology mentions two basic, not-too-anthropocentric sets of criteria to analyze intelligence. Edward Wilson's "behavioral hierarchy" divides it into three general levels of complexity, the last two of which are limited to animals, since they need a nervous structure to carry information: #Stimulus → reaction process: simple biochemical mechanisms produce an automatic reaction to each relevant stimulus. Bacteria and protozoa can orient themselves in the environment and look for nourishment by following chemical and luminous signals; animals at this level include sponges, coelenterates and flatworms. #Directed learning: arthropods, cephalopods and most vertebrates have a complex nervous system that allows the individual development of sterotyped behaviours as a response to familiar situations; however, they still rely often on genetic-based inherited behaviours (instincts). #Generalized learning: primates, canids, corvids and few other animals (see "Intelligence on Earth") retain a wide range of memories, allowing the formulation of complex behaviours that can be modified and adapted to new situations and the generalization of patterns. Only a few basic biological functions are still committed to instinct. The aerospace computer scientist Roger MacGowan has produced a list of five basic criteria that he considers both necessary and sufficient to determine intelligence itself in any conceivable lifeform: #'Input': the sensory input from the environment, deeded as raw material for intelligence to work on; #'Storage': conservation of information as memories for a future need, necessary for learning; #'Deduction': the ability to insert currently received information in learned categories based on memories; #'Induction': the extension of past experience to expected future events; #'Output': physical or mental activity as response to processed information. Among the numerous capabilities that make up intelligence, these seem to be the most important: Categorization A capability of inductive categorization is necessary to learn about the environment: an animal stung by a wasp learns to avoid everything that looks yellow and black. More complex is the formation of categories based on abstract concepts: in the Vaughan experiment, some pigeons exposed to images randomly distributed in two arbitrary sets learned to peck, rewarded with food, only the images of a particular set, considering as relevant property the membership to it, and not any perceptible feature. Category:Intelligence Category:Speculative biology Category:Content Category:Community Memory Memory is in turn a combination of many different features. The most known is the spatial memory, well expressed by animals that stockpile food, such as Clark's nutcracker, tits, jays and squirrels. Despite their extremely tiny nervous system, bees can remember for days data met only once, and for all life data met at least three times. Spatial cognition The classic labyrinth test is solved in different species with different abilities: ants and bees mark with chemicals the places where they've already been, pigeons commit to memory the environmental features, rats get to the treat at the centre of a radial labyrinth (a cetral platform with a number of arms, generally 8, only one of which contains food; it forces the rat to start anew from the centre each time) visualizing its geometric structure. Even the slime mold Physarum polycephalum, a colonial amoeba, is able to find the shortest path to exit from a labyrinth by scouting it with tendrils, mantening the colony cohesive. Reasoning and problem solving Over the course of several experiments, chimpanzees proved to be able to understand the operation of a structure and use it to their own advantage, for example to get food, not simply through trial-an-error or previous training, but through preemptive reasoning; New Caledonian crows appear to be able to comprehend and implement cause-and-effect relationships, and even combine more tools (also see below). Category:Intelligence Category:Speculative biology Category:Content Category:Community Self-consciousness Also see: Consciousness Self-consciousness is generally understood as the capability of an individual to distinguish itself from the environment (including other individuals) without a direct intervention of sense organs. It's very difficult to test this capability in animals: the mirror test, in which it's controlled whether an animal is able to see in a mirror a mark on its body (and therefore recognize the image in the mirror as its own image, and not another individual) has been passed by chimpanzees, gorillas, european magpies, some species of cetaceans and an elephant, but not monkeys. While of some significance, the mirror test is thought to be incomplete and biased towards sight. Another factor currently under study is metacognition ("knowing to know"), the perception of one's own knowledge: in a 2009 experiment, some rhesus monkeys were able to evaluate the tests' difficulty by expressing uncertainty for the most complex ones, instead of trying a random answer. Math Many animals are able to distinguish different quantities: angelfish seem to be able to recognize the large set, provided that it is at least two times bigger than the other; pigeons and other birds can sort sets of objects from the smaller to the bigger; rhesus monkeys can recognize the smaller between sets whose elements look different, and the same number of visual and auditive stimuli; african elephants are able to perform simple additions, computing the total number of apples left in buckets in different times. Symbol interpretation The capability for abstraction is extremely rare in the animal kingdom: most species reacts to an object's depictions only if realistic enough. It's strictly related to the abilities of categorization and prototype formation; for example, a human can see a face in a simple : ), identifying two dots and a curved line as the basic elements of a human face. The recognising of abstract symbols, that do not resemble at all to the symbolised object, has probably been developed with the association between animals and their footprints. Using complex languages requires symbolic abstraction to associate concepts with words (see below). Mind theory It's called "mind theory" the capability to attribute mental states (knowledge, beliefs, intentions, desires...) to other individuals: it's likely the single biggest incentive to intelligence in a social species. A baboon does not warn others about a danger they can't see, since it ascribes to everyone the same knowledge it has, as 3-years old children do. Chimpanzees, however, often take food for themselves only when they know individuals of higher rank can't see them, and they can deceive others giving them false notions: for example, pretending to be hurt or sick to get more food (see here, pages 41-47). Many of the abilities above described exist, even well-developed, in organisms that are not thought to be especially intelligent, such as spatial memory in migratory birds and seed-stockpilers, or the orientation and complex language of bees. They're, however, highly specialized skills; we can give a new definition of "intelligence" as the capability of integrating and coordinate these skills together. This capability belongs, above all, to primates, cetaceans and some groups of birds (see Intelligence on Earth). Encephalization quotient Encephalization quotient, or EQ, is a way to measure the brain's development in an animal (or, more properly, a vertebrate) species. It could be thought that mere brain size would be indicative of intelligence, but let's consider this list of thirty animal species, ordered by brain mass (data from here, here and here): This is not entirely useful. Obviously bigger animals need bigger brains to operate at the same level of cognition: due to its sheer mass, a hippopotamus needs a bigger brain than a cat. On the other hand, a man and a walrus, a Troodon and a Stegosaurus, an ostrich and a great white shark all have similar brain sizes but wildly different body sizes: a Stegosaurus had (likely) a brain about as big as that of a Troodon, but inside a 90 times as heavy body! We need a more refined approach. This list gives the same species ordered according to a new feature, the brain-to-body mass ratio, that is, the brain mass divided by the body mass: That's better, but there are still many issues. For one, not only man is not at the top, but instead there is the barely-brained rotifer, while the african elephant, regarded as very intelligent, is confined below cows and goldfish, and the sperm whale is at the bottom, below a frog! A chimpanzee shares the ranking with a bee, while two breeds of dogs end up in very different places. Clearly this method does not work, either. This is due to allometry, a relationship between organs in different-sized body expressed with an exponential function. Since changing the size of an object with a constant shape doesn't leave unchanged its properties, to keep the same functions, the brain has to be scaled differently from the body: the exponent can vary, according to different estimates, from 0.3 to 0.75, with a likely average of 0.66 for mammals (for cold-blooded animals it should be lower, and for invertebrates a wholly different method might be needed). That means that, if the body becomes n times heavier, the brains need to become n0.66 heavier to perform the same work. Let's thus define encephalization quotient as a relationship between the brain mass and the 0.66 power of the body mass: Q = 100·E/S0.66, where E is the brain mass and S the body mass. Much, much better. We get a reasonable-looking ranking, that still holds some surprises: cattle still appears above many other mammals, including the sperm whale, and the walrus and the octopus are surprisingly high. Still, the 0.66-method is generally well supported by known data. Generally, fish hardly go beyond 0.05 EQ, amphibians and reptiles 0.01 EQ, while birds and mammals go from 0.3 to 1.5 EQ. As an average, herbivores (with the notable exception of the elephants) and insectivores stay under 1.0 EQ, while carnivores (especially cetaceans) and omnivores (especially primates) are above (see also here); social animals rank higher than solitary animals (dogs higher than cats, horses and lions higher than rats). Only very few species exceed 2 EQ, with the bottlenose dolphin and man at the very top. Tool use It could be said, if "tool" means simply an object extraneous to the body that an organism uses to extend its influence of the environment, that instinctive tool use is extremely widespread throughout the animal kingdom. Archerfishes spit water on their preys, reduviid bugs camouflage with remnants of killed preys, termites build their nests with mud and detritus, striated herons bait fishes with leaves and fethers. There are also many learned and seemingly reasoned form of object use: octopi protect themselves with coconut and mollusk shells; dolphins use shells to trap fish and sponges to protect their snout; an alaskan brown bear has been observed using a stone to get rid of patches of moulting fur; elephants use branches to eliminate parasites, open passings in electric fences with rocks and cover water pools with bark to prevent evaporation; gorillas and orangutans measure with sticks the depths of the water streams they wade, and at least one orangutan has been seen trying to fish with a spear. The Galapagos woodpecker finch extracts larvae from bark using cactus spine, often breaking them to make them more manageable, obtaining up to half of their food with this method. Using rocks to get food from hard-shelled objects seems to be an especially common skill: chimpanzees and capuchin monkeys breaks do this to nuts, sea otters to the mollusks and sea urchins they carry on their chest, wrasses to bivalves; egyptian vultures and seagulls let respectively bones and oysters fall to the ground. Chimpanzees, after man, may be the most skillful tool users. They extract termites from their nests and honey from beehives with sticks, use moss and chewed leaves as sponges to carry water, rocks and branches to fend off predators, and even wooden spears to hunt bushbabies. New Caledonian crows manage not only to manipulate food, but also to build more tools, for example bending wire to make a hook, to use tools to safely examine possibly dangerous items, and even to get other secondary tools, something that not even chimpanzees are able to do. Category:Intelligence Category:Speculative biology Category:Content Category:Community Language Consciousness Examples in speculative biology References *Extraterrestrial intelligence (Xenology) (also see further pages) Category:Intelligence Category:Speculative biology Category:Content Category:Community